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Abstract  

The spectrometric system for ionizing radiation measurement with pile-up rejection and counting losses correction has been described. The results for HpGe, Ge(Li), Si(Li) and surface barrier detectors have been presented. The total count rate ranged from 500 to 105 cps and different radioisotopes have been used. The counting losses correction accuracy has been within ±1% with tenfold reduction of background from pile-up pulses. The possibility of the system application for radiation intensity measurement of the mixture of short- and longlived radioisotopes has been discussed.

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Abstract  

A relatively simple method of sulphur determination in drill cores of calcium carbonate matrix is described. The method is based on the combination of measurements of backscattered beta-particles and transmitted low energy gamma-radiation intensities. The transmitted gamma-radiation measurement corrects the errors of sulphur determination caused by the varying strontium sulphate and silicon dioxide content. The method has been tested on 170 samples. It was estimated that the standard deviation of sulphur determination does not exceed 2.5% of sulphur. The apparatus for routine absorption measurement is also described.

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Abstract  

A method of uranium determination in organic and aqueous solutions has been developed, based on fluorescence L X-ray excitation with a109Cd source of several mCi activity and counting the excited Lα lines with a proportional counter. To eliminate uranium X-ray absorption by the accompanying elements the intensity of the source radiation (Ag K) transmitted through the analysed solution is measured. The ratio of these two intensities is independent of other elements present in the solution over a very broad range of concentration. The analysis time does not exceed 5 minutes. The precision and accuracy of this method in the range 0.5 to 100 g U/1 are comparable to those of the classical titrimetric method.

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Abstract  

The energy dispersive X-ray fluorescence method of Pb and Ag determination in metallic copper is described. Radioisotopic sources of57Co and241Am/target have been used for excitation and Si(Li) and hyperpure Ge spectrometers for spectra analysis. The standard deviation of Pb and Ag determination for a single measurement is 0.015 and 0.012%, respectively.

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Abstract  

The plutonium determination by alpha-particle spectrometry with semiconductor detectors in the presence of uranium has been described. It has been found that plutonium as well as uranium can be electrodeposited quantitatively on nickel or stainless steel discs from solutions in isopropanol. The time of deposition does not exceed 35–40 min. The determination of plutonium is possible within the uranium to plutonium weight ratio of 4000 with the accuracy better than 2%.

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Abstract  

The possibility of application of the radioactive source excited X-ray fluorescence analysis for titanium and iron determination in kaolins to the routine test of the refinement process has been studied. The iron content can be determined with a simple counting system using a single-channel pulse height analyser, argon filled proportional counter and109Cd source of 3 mCi for the excitation of K Fe rays. The samples were analysed both as pellets and powders. The iron content ranged from 0.2–2.5% and titanium from 0.1–0.64%. For simultaneous determination of titanium and iron a Si(Li) spectrometer has been used. The238Pu source has been used for K Fe and K Ti excitation. It is the most convenient source for simultaneous determination of titanium and iron.55Fe is the most efficient source for the determination of titanium alone. The best values of precision and determination limit have been achieved for iron with238Pu and for titanium with55Fe.

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Abstract  

An analytical procedure for determination of Fe, Ti, V, Ni, Co and Cu, the most important constituents of the polymetallic ore has been developed. Twenty four powdered samples were prepared from the material taken in various places of the ore deposit. The samples were analyzed by wavelength dispersive (WD) and energy dispersive (ED) XRF method. The EDXRF method was applied using radioisotope source as well as a low power X-ray tube (Rh-anode) for excitation of the characteristic K-line radiation of the elements. A Si(Li) detector was used for the detection of radiation. The detection limits and precision of the analytical procedures, using reference materials, were estimated. The accuracy of the different XRF techniques is discussed. The developed analytical procedures based on the XRF method are rapid and quite simple. They can be useful for exploration data accumulation.

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Abstract  

The computational method for the rapid evaluation of gamma and X-ray spectra observed by semiconductor detectors in radiometric analysis in presented using a simple peak shape function. The computer programme includes a minimizing routine based on the modified Newton-Raphson method giving a minimized vector of the parameters more rapidly than the conventional approach. The spectra of some gamma-ray emitting fission products and X-ray spectra excited by radioisotopes of materials from copper ore processing were studied. It was found that the simple Gaussian peak function gives the results equivalent to the total peak area method.

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Abstract  

A gamma-ray spectrometer with a passive and an active shield is described. It consists of a HPGe coaxial detector of 42% efficiency and 4 NaI(Tl) detectors. The energy output pulses of the Ge detector are delivered into the 3 spectrometry chains giving the normal, anti- and coincidence spectra. From the spectra of a number of 137Cs and 60Co sources a Compton suppression factor, SF and a Compton reduction factor, RF, as the parameters characterizing the system performance, were calculated as a function of energy and source activity and compared with those given in literature. The natural background is reduced about 8 times in the anticoincidence mode of operation, compared to the normal spectrum which results in decreasing the detection limits for non-coincident gamma-rays up to a factor of 3. In the presence of other gamma-ray activities, in the range from 5 to 11 kBq, non- and coincident, the detection limits can be decreased for some nuclides by a factor of 3 to 5.7.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: J. Parus, W. Ratynski, T. Zółtowski, J. Tys, J. Kierzek, E. Cieślak, and J. Kownacki
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